Coach Norv Turner (right) reportedly will be fired at the end of the season. Hayne Palmour IV • U-T

The Chargers have taken the first step, but this shouldn’t be a 12-step program.

The reported purging of A.J. Smith and Norv Turner was essential to the organization’s health, but this should signal a rejuvenation, not an all out rebuild.

To most people, San Diego reaching the playoffs next year seems about as probable as Eli Manning succeeding Bob Filner. But just think of it like fourth and 29: It’s a lot more likely than you’d think.

Aside from a set of JV cornerbacks and a matador offensive line, the Chargers have a postseason-caliber team. That may be difficult to see through the fog the of this season, but it’s the truth.

So any temptation to gut this roster needs to be resisted. Now, more than ever, foresight must be 20/20, too.

The cliché going around right now is that Philip Rivers’ window is closing. That’s convenient to say when his efficiency has been skiing down a black-diamond slope for two years, but it’s just not true.

It’s not a closing window to blame so much as it is a collapsing pocket. In the years he’s had even a morsel of protection, Rivers has been among the NFL’s elite quarterbacks.

Peyton Manning is 36 right now and perhaps the leading MVP candidate. Tom Brady is 35 and playing as well as when he was 25.

And while the 30-year-old Rivers has never been on the same Hall of Fame plane as of either those guys, it’s silly to think that he couldn’t find his old form with another second or two to pass.

He certainly has the targets. Malcom Floyd, Robert Meachem and Danario Alexander may not possess Vincent Jackson-like dynamism, but they can certainly keep a first-down marker from relaxing. Antonio Gates may be descending from his skyscraping peak, but he’s still a few dozen stories above most in the league.

And with decent safeties, a developing defensive line, and a daunting linebacker core, the Chargers’ position as the NFL’s ninth-best defensive team only stands to improve.

Now, the task is to hand those ingredients to the proper chef.

Nowhere in professional sports can a coach influence success like he can in football.

Jim Harbaugh flipped a 6-10 49ers squad into a 13-3 Superstorm in his first year wearing an NFL headset. Bill Belichick’s nine straight seasons with at least 10 wins includes an 11-5 team QB’d by Matt Cassel.

Whether it’s Jon Gruden or Chip Kelly or an unrenowned phenom, the Chargers need a coach who cannot only instruct and inspire, but instill a sense of self-belief that Turner consistently dissolved. If games were three quarters long, the Bolts are 8-4 right now. Heartbreaking for fans, but will-breaking for players.

But it turns out that you can pull the plug and plug a hole at the same time. As A.J. and Norv’s tenures end, the repairs can begin.

Chargers director of player personnel Jimmy Raye appears to be Smith’s replacement, and if he can draft wisely — mainly by stocking up on offensive linemen and defensive backs — San Diego can be playing in mid-January by 2014.